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R. J. SAGHERS. 'M AAAAAAAAAAAAA RI NNNNNNNNNNN No. 518,826. Patented Apr. 24, 1894.

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UNITED STATES PATE-NT OFFICE.

RALPH J..SAOHERS, OF NEW YORK, N. Y.

MANUFACTURE OF PRINTING-PLATES.

SPECIFICATION forming part of Letters Patent No. 518,826, dated April 24, 1894, Application filed J' une 28, 1892. Renewed November 10, 1893. Serial No. 490,588. (No specimens.)

.To @ZZ whom it' may concern.-

Be it known that I, RALPH J. SAonERs, a citizen of the United States, and a resident of the city, county, and State ofA New York, have invented certain new and useful Improvements in the Manufacture of Printing-Plates, of which the following is a specification.

This invention relates to an improved process of making relief-plates for printing purposes, and it consists of the following successive steps: first, coating the surface of a soft metal plate with a layer of a hard metal by electro-deposition, secondly, transferring the picture to be produced by photography or otherwise onto the metallic coating of the plate, third, etching the uncovered parts of the plate by galvanocaustic means until the uncovered parts of the hard metal coating are removed, fourth, deep-etching the uncovered parts by the use of suitable acids.-

In the accompanying drawings, Figure 1 represents a metal-plate which illustrates the dierent steps of my improved process of making relief printing plates. Fig. 2 is'a vertical longitudinal section of the same, on line 2 2, Fig. 1, and Fig, 3 is a section of the iinished relief plate.

Similar letters of reference indicate corresponding parts.

In carrying out my process of making reliefplates for printing purposes, a plate of typemetal, zinc or other soft metal is coated by electro deposition with a layer of nickel, brass, copper, iron or other hard metal. To this surface-coating is transferred by the photographic process or otherwise the picture to be produced as shown at A, Figs. l and 2, and the uncovered portions of the plate are etched away by galvanocaustic means, until the metal, of which the body of the plate is composed, appears as shown at B. When a halftone plate is to be produced the plate is then subjected to a slight chemical etching, after which the half-tone relief-plate is ready for iin al retouching, blocking, 85o. When the relief-plate isv to be in lines or stipples, the plate is rolled up with fatty inks by means of a hard roller and then powdered in with dragons-blood, the surplus of which is carefully brushed offr while the remaining powder I is melted in so as to produce a thin acid-proof surface-coating for the parts in relief, as shown at C, in Figs. l and 2. The plate is next subjected to a deep-etching process by the use of a suitable acid, after which the plate is cleaned of all adhering resin and etched again for a short while, washed with water and dried, as shown at D. The result is a metal foundation-plate in which the parts in relief are covered by a protecting surface coating of a hard `metal from which a much larger number of impressions can be taken than from the ordinary relief-printing plates and which can be produced inamuch shorter time by my process than by the process heretofore in use.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl l. A relief printing plate consisting of a soft metal foundation and a surface coating of hard metal, said plate having an etched or engraved face, the depressed portions of which extend through the surface coating into the soft/metal base, the edges of said coating remaining on the raised portions being sharp, substantially as set forth.

2. The process herein described of making relief-plates for printing purposes, which consists of the following steps: first, coating a soft metal plate by electro deposition with a surface-layer of a hard metal, second, transferring the picture to be produced on that plate, third, etching the uncovered partsbygalvanocaustic means, and fourthly, deep-etching by the use of a suitable acid, substantially as set forth.

3. The process of making relief plates for printing purposes, which consists in coating a soft metal plate by electro-deposition with a surface-layer of 4a hard metal; then transferA ringthe picture to be produced onto said plate; and then etching the uncovered parts thro ugh the surfacelayer, substantially asset forth.

In testimony that I claim the foregoing as my invention I have signed my naine in presence of two. subscribing witnesses.

RALPH J. SAOHERS. 

